Integrated circuits are typically tested to determine how they will perform when used in different scenarios. Testing is performed either by subjecting the integrated circuit to a set of physical tests, or by simulating how a model of the integrated circuit would perform under those same set of physical tests. Simulated testing provides integrated circuit designers and users with the means to determine how a circuit will perform under model conditions. Most model conditions, however, do not account for gross variations in circuit performance due to problems such as manufacturing defects, improper installation, etc. Therefore, prior to final use of a particular integrated circuit, it is advisable that physical testing be performed which would account for problems such as manufacturing defects.
When implementing physical tests accounting for conditions such as manufacturing defects and improper installations, a test engineer determines what potential problems could arise and manually tests the integrated circuit by either open-circuiting a pin or set of pins or short-circuiting a pin or set of pins. Depending on the number of pins on the integrated circuit undergoing the tests, hundreds of combinations of open circuits and short circuits may need to be tested. Alternatively, the integrated circuit may be tested electronically. For example, relays or solid state transistors may be used to test the integrated circuit.